A Screen-Based Acuity Loss Simulation Tool:Gaussian Blur as a Simple Standardised Simulation Method for Accessibility and HCI Studies

Accessible and scalable methods for simulating vision loss are essential for studying accessibility and human–computer interaction under visual constraints. Traditional approaches, such as simulation spectacles, require in-person testing and limit remote participation. This study evaluates Gaussian blur applied to electronic displays as an alternative means of simulating visual acuity loss. Thirty-seven participants completed visual-acuity tests using ETDRS charts and a screen-based tumbling-E test on monitors of three pixel densities (94, 170, 218 PPI) under normal, moderate, and severe impairment induced by simulation spectacles. They then performed 29 blurred vision tests with varying Gaussian-blur standard deviations (σ). Regression models showed a strong log-linear relationship between blur strength and measured visual-acuity loss and accounted for over 90% of the variance, allowing estimation of σ needed to simulate specific degrees of visual impairment to support low-cost accessibility testing and remote investigation of perceptual and attentional processes in degraded visual conditions